I can mentally add 10 or 100 to any number.
Problem 1
48 + 10 = _____
Hint: When you add 10, only the tens digit changes. Add 1 to the tens place.
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Problem 2
34 + 10 = _____
Hint: When you add 10, only the tens digit changes. Add 1 to the tens place.
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Problem 3
73 + 10 = _____
Hint: When you add 10, only the tens digit changes. Add 1 to the tens place.
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Problem 4
55 + 10 = _____
Hint: When you add 10, only the tens digit changes. Add 1 to the tens place.
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Problem 5
75 + 10 = _____
Hint: When you add 10, only the tens digit changes. Add 1 to the tens place.
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Problem 6
77 - 10 = _____
Hint: When you subtract 10, only the tens digit changes. Subtract 1 from the tens place.
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Problem 7
60 - 10 = _____
Hint: When you subtract 10, only the tens digit changes. Subtract 1 from the tens place.
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Problem 8
41 - 10 = _____
Hint: When you subtract 10, only the tens digit changes. Subtract 1 from the tens place.
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Problem 9
47 - 10 = _____
Hint: When you subtract 10, only the tens digit changes. Subtract 1 from the tens place.
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Problem 10
76 - 10 = _____
Hint: When you subtract 10, only the tens digit changes. Subtract 1 from the tens place.